Linux management and generation of Rate information for TCP. More...

#include "tcp-rate-ops.h"

Inheritance diagram for ns3::TcpRateLinux:

Collaboration diagram for ns3::TcpRateLinux:

Public Types
typedef void(*	TcpRateSampleUpdated) (const TcpRateSample &sample)
	TracedCallback signature for tcp rate sample update events. More...

typedef void(*	TcpRateUpdated) (const TcpRateConnection &rate)
	TracedCallback signature for tcp rate update events. More...

Public Member Functions
	~TcpRateLinux () override

void	CalculateAppLimited (uint32_t cWnd, uint32_t in_flight, uint32_t segmentSize, const SequenceNumber32 &tailSeq, const SequenceNumber32 &nextTx, const uint32_t lostOut, const uint32_t retransOut) override
	If a gap is detected between sends, it means we are app-limited. More...

const TcpRateSample &	GenerateSample (uint32_t delivered, uint32_t lost, bool is_sack_reneg, uint32_t priorInFlight, const Time &minRtt) override
	Generate a TcpRateSample to feed a congestion avoidance algorithm. More...

const TcpRateConnection &	GetConnectionRate () override

void	SkbDelivered (TcpTxItem *skb) override
	Update the Rate information after an item is received. More...

void	SkbSent (TcpTxItem *skb, bool isStartOfTransmission) override
	Put the rate information inside the sent skb. More...

Public Member Functions inherited from ns3::Object
	Object ()
	Constructor. More...

	~Object () override
	Destructor. More...

void	AggregateObject (Ptr< Object > other)
	Aggregate two Objects together. More...

void	Dispose ()
	Dispose of this Object. More...

AggregateIterator	GetAggregateIterator () const
	Get an iterator to the Objects aggregated to this one. More...

TypeId	GetInstanceTypeId () const override
	Get the most derived TypeId for this Object. More...

template<typename T >
Ptr< T >	GetObject () const
	Get a pointer to the requested aggregated Object. More...

template<>
Ptr< Object >	GetObject () const
	Specialization of () for objects of type ns3::Object. More...

template<typename T >
Ptr< T >	GetObject (TypeId tid) const
	Get a pointer to the requested aggregated Object by TypeId. More...

template<>
Ptr< Object >	GetObject (TypeId tid) const
	Specialization of (TypeId tid) for objects of type ns3::Object. More...

void	Initialize ()
	Invoke DoInitialize on all Objects aggregated to this one. More...

bool	IsInitialized () const
	Check if the object has been initialized. More...

Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter >
	SimpleRefCount ()
	Default constructor. More...

	SimpleRefCount (const SimpleRefCount &o[[maybe_unused]])
	Copy constructor. More...

uint32_t	GetReferenceCount () const
	Get the reference count of the object. More...

SimpleRefCount &	operator= (const SimpleRefCount &o[[maybe_unused]])
	Assignment operator. More...

void	Ref () const
	Increment the reference count. More...

void	Unref () const
	Decrement the reference count. More...

Public Member Functions inherited from ns3::ObjectBase
virtual	~ObjectBase ()
	Virtual destructor. More...

void	GetAttribute (std::string name, AttributeValue &value) const
	Get the value of an attribute, raising fatal errors if unsuccessful. More...

bool	GetAttributeFailSafe (std::string name, AttributeValue &value) const
	Get the value of an attribute without raising errors. More...

void	SetAttribute (std::string name, const AttributeValue &value)
	Set a single attribute, raising fatal errors if unsuccessful. More...

bool	SetAttributeFailSafe (std::string name, const AttributeValue &value)
	Set a single attribute without raising errors. More...

bool	TraceConnect (std::string name, std::string context, const CallbackBase &cb)
	Connect a TraceSource to a Callback with a context. More...

bool	TraceConnectWithoutContext (std::string name, const CallbackBase &cb)
	Connect a TraceSource to a Callback without a context. More...

bool	TraceDisconnect (std::string name, std::string context, const CallbackBase &cb)
	Disconnect from a TraceSource a Callback previously connected with a context. More...

bool	TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb)
	Disconnect from a TraceSource a Callback previously connected without a context. More...

Static Public Member Functions
static TypeId	GetTypeId ()
	Get the type ID. More...

Static Public Member Functions inherited from ns3::TcpRateOps
static TypeId	GetTypeId ()
	Get the type ID. More...

Static Public Member Functions inherited from ns3::Object
static TypeId	GetTypeId ()
	Register this type. More...

Static Public Member Functions inherited from ns3::ObjectBase
static TypeId	GetTypeId ()
	Get the type ID. More...

Private Attributes
TcpRateConnection	m_rate
	Rate information. More...

TcpRateSample	m_rateSample
	Rate sample (continuously updated) More...

TracedCallback< const TcpRateSample & >	m_rateSampleTrace
	Rate Sample trace. More...

TracedCallback< const TcpRateConnection & >	m_rateTrace
	Rate trace. More...

Additional Inherited Members
Protected Member Functions inherited from ns3::Object
	Object (const Object &o)
	Copy an Object. More...

virtual void	DoDispose ()
	Destructor implementation. More...

virtual void	DoInitialize ()
	Initialize() implementation. More...

virtual void	NotifyNewAggregate ()
	Notify all Objects aggregated to this one of a new Object being aggregated. More...

Protected Member Functions inherited from ns3::ObjectBase
void	ConstructSelf (const AttributeConstructionList &attributes)
	Complete construction of ObjectBase; invoked by derived classes. More...

virtual void	NotifyConstructionCompleted ()
	Notifier called once the ObjectBase is fully constructed. More...

Related Functions inherited from ns3::ObjectBase
static TypeId	GetObjectIid ()
	Ensure the TypeId for ObjectBase gets fully configured to anchor the inheritance tree properly. More...

Detailed Description

Linux management and generation of Rate information for TCP.

This class is inspired by what Linux is performing in tcp_rate.c

Definition at line 195 of file tcp-rate-ops.h.

Member Typedef Documentation

◆ TcpRateSampleUpdated

typedef void(* ns3::TcpRateLinux::TcpRateSampleUpdated) (const TcpRateSample &sample)

TracedCallback signature for tcp rate sample update events.

The callback will be fired each time the rate sample is updated.

Parameters

[in] sample The rate sample that will be passed to congestion control algorithms.

Definition at line 246 of file tcp-rate-ops.h.

◆ TcpRateUpdated

typedef void(* ns3::TcpRateLinux::TcpRateUpdated) (const TcpRateConnection &rate)

TracedCallback signature for tcp rate update events.

The callback will be fired each time the rate is updated.

Parameters

[in] rate The rate information.

Definition at line 236 of file tcp-rate-ops.h.

Constructor & Destructor Documentation

◆ ~TcpRateLinux()

ns3::TcpRateLinux::~TcpRateLinux ( )

inlineoverride

Definition at line 205 of file tcp-rate-ops.h.

Member Function Documentation

◆ CalculateAppLimited()

void ns3::TcpRateLinux::CalculateAppLimited	(	uint32_t	cWnd,
		uint32_t	in_flight,
		uint32_t	segmentSize,
		const SequenceNumber32 &	tailSeq,
		const SequenceNumber32 &	nextTx,
		const uint32_t	lostOut,
		const uint32_t	retransOut
	)

overridevirtual

If a gap is detected between sends, it means we are app-limited.

TODO What the Linux kernel is setting in tp->app_limited? https://elixir.bootlin.com/linux/latest/source/net/ipv4/tcp_rate.c#L177

Parameters

cWnd	Congestion Window
in_flight	In Flight size (in bytes)
segmentSize	Segment size
tailSeq	Tail Sequence
nextTx	NextTx
lostOut	Number of lost bytes
retransOut	Number of retransmitted bytes

Implements ns3::TcpRateOps.

Definition at line 140 of file tcp-rate-ops.cc.

References ns3::TcpRateOps::TcpRateConnection::m_appLimited, ns3::TcpRateOps::TcpRateConnection::m_delivered, m_rate, m_rateTrace, NS_LOG_FUNCTION, and segmentSize.

Referenced by TcpRateLinuxBasicTest::SendSkb().

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◆ GenerateSample()

const TcpRateOps::TcpRateSample & ns3::TcpRateLinux::GenerateSample	(	uint32_t	delivered,
		uint32_t	lost,
		bool	is_sack_reneg,
		uint32_t	priorInFlight,
		const Time &	minRtt
	)

overridevirtual

Generate a TcpRateSample to feed a congestion avoidance algorithm.

This function will be called after an ACK (or a SACK) is received. The (S)ACK carries some implicit information, such as how many segments have been lost or delivered. These values will be this function input.

Parameters

delivered	number of delivered segments (e.g., receiving a cumulative ACK means having more than 1 segment delivered) relative to the most recent (S)ACK received
lost	number of segments that we detected as lost after the reception of the most recent (S)ACK
priorInFlight	number of segments previously considered in flight
is_sack_reneg	Is SACK reneged?
minRtt	Minimum RTT so far

Returns: The TcpRateSample that will be used for CA

Implements ns3::TcpRateOps.

Definition at line 57 of file tcp-rate-ops.cc.

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◆ GetConnectionRate()

const TcpRateConnection& ns3::TcpRateLinux::GetConnectionRate ( )

inlineoverridevirtual

Returns: The information about the rate connection

Implements ns3::TcpRateOps.

Definition at line 224 of file tcp-rate-ops.h.

References m_rate.

◆ GetTypeId()

TypeId ns3::TcpRateLinux::GetTypeId ( void )

static

Get the type ID.

Returns: the object TypeId

Definition at line 39 of file tcp-rate-ops.cc.

References m_rateSampleTrace, m_rateTrace, ns3::MakeTraceSourceAccessor(), and ns3::TypeId::SetParent().

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◆ SkbDelivered()

void ns3::TcpRateLinux::SkbDelivered ( TcpTxItem * skb )

overridevirtual

Update the Rate information after an item is received.

When an skb is sacked or acked, we fill in the rate sample with the (prior) delivery information when the skb was last transmitted.

If an ACK (s)acks multiple skbs (e.g., stretched-acks), this function is called multiple times. We favor the information from the most recently sent skb, i.e., the skb with the highest prior_delivered count.

Parameters